1. Field of the Invention
The present invention relates to power control apparatuses, and more particularly, to a consensus-based power control apparatus applicable to a grid system having at least two power generating apparatuses.
2. Description of Related Art
In a grid system constituted by a plurality of power generating apparatuses such as synchronous generators, wind power generators and water power generators, since the power generating apparatuses usually generate significantly different real power input signals (representing actual real power outputs of the apparatuses) or reactive power input signals (representing actual reactive power outputs of the apparatuses) and the grid system lacks an ability to distribute the real power input signals and the reactive power input signals of the power generating apparatuses, the real power input signals and the reactive power input signals of the power generating apparatuses cannot become (or tend to become) uniform or have predetermined ratios, thus adversely affecting the overall energy stability of the grid system.
FIG. 1 is a schematic block diagram of a conventional synchronous generator 1. Referring to FIG. 1, the synchronous generator 1 has a first subtraction unit 11, a second subtraction unit 12, an inertia unit 13, a first integral unit 14, a friction unit 15 and a second integral unit 16.
The first subtraction unit 11 subtracts a real power input signal Pe from a real power command signal PM to generate a real power difference signal A1. The second subtraction unit 12 subtracts a feedback frequency signal A2 from the real power difference signal A1 to generate a real power output signal A3. The inertia unit 13 multiplies the real power output signal A3 by an inertia constant to generate a frequency differential signal {dot over (ω)}. The first integral unit 14 integrates the frequency differential signal {dot over (ω)} to generate a frequency signal ω. The friction unit 15 multiplies the frequency signal ω by a friction constant to generate the feedback frequency signal A2. The second integral unit 16 integrates the frequency signal ω to generate an electric angle signal θ.
However, when a plurality of synchronous generators 1 are applied in a grid system, since the grid system lacks the ability to distribute real power input signals Pe and reactive power input signals (not shown) of the synchronous generators 1, the real power input signals Pe and the reactive power input signals of the synchronous generators 1 cannot become (or tend to become) uniform or have predetermined ratios. Consequently, the overall energy of the grid system lacks stability.
Therefore, there is a need to provide a consensus-based power control apparatus so as to overcome the above-described drawbacks.